Dan Wheeler's Astro Hydroboost Thread

EDIT 4/11/202 - I've recently fixed all the pic links.
Also, if you need a larger master cylinder due to large tires, check out my 1.5" Ford F350 MC and hboost thread titled:
"Dan Wheeler's One-Ton 1.5" Bore Master Cylinder and Hydroboost Thread"
(it won't allow me to link to it here so you'll have to search for it)

Recently, I've had several people ask me about my hydroboost setup and I noticed my old astroboost thread is outdated so I'm starting this new one with updated pics, info and part numbers. It's not the end-all/be-all hydroboost thread, just how I did it. The part numbers are from www.SummitRacing.com

Big Parts:
- 1 junkyard hydroboost unit from an Astro/Safari van
- 1 junkyard master cylinder from an Astro/Safari van
- 1 extra large brake fluid reservoir from the other Astro/Safari van in the same row
- 1 4x4x2 steering gearbox from eBay (78/79 Bronco case w/ F150 internals)

I want my pressure lines to be -6 AN. I use the Russell Powerflex braided stainless steel hose which is specifically designed for power steering. Do not use any pressure lines or fittings that are not rated for power steering/hydraulic.

Inputs/Outputs:
- Hydroboost input = M16x1.5 bubble flare
- Hydroboost output = M18x1.5 bubble flare
- 4x4x2 Steering Box input = 5/8-18 inverted flare
- Saginaw "Canned Ham" P/S pump can be either 3/8ths inverted flare or M16x1.5 bubble flare
- Explorer P/S pump is proprietary/weird. You can get the -6AN fitting you need from https://leepowersteering.com/collec...-with-seat-ford-pumps-racks-pinions-16mm-to-6 for about $20.

Explorer P/S pump -6AN fitting from Lee Power Steering (aluminum washer is upside-down in this pic)



Fittings/Parts:
You will need (2) different bubble flare to -6AN fittings for the hydroboost unit:

- RUS-648060 Fitting, Straight, AN Flare to Metric, Stainless Steel, -6 AN to 16mm x 1.5 Male
- RUS-648080 Fitting, Straight, AN Flare to Metric, Steel, -6 AN to 18mm x 1.5 O-Ring

If you have the Saginaw canned ham pump, you will need (2) of the above RUS-648060 fittings. If you have an older Saginaw canned ham pump with 3/8ths inverted flare, you'll need a -6AN conversion fitting for that (sorry no part number)

If you have the 4x4x2 box you will need a -6 AN to 5/8-18 NPT fitting:
- RUS-640380 Fitting, Straight, -6 AN Male to 5/8-18 in. Inverted Flare, Steel, Zinc, Each

you may also need a fitting for the steering box low pressure return which I believe is 3/8ths inverted flare. You can buy a little piece of pre-flared hard line from NAPA with fittings for this.

You will need some power steering hose:
RUS-632620 Hose, Powerflex, Braided Stainless Steel, -6 AN, 10 ft.

You will need hose ends. I used (4) 90 degree bend hose ends:
RUS-620421 Fitting, Hose End, Power Steering, 90 Degree, -6 AN Hose to Female -6 AN

You will want a brake proportioning valve to adjust the front/back bias:
http://www.summitracing.com/parts/SUM-G3905/

Don't use the Astro van valve - its not worth it. The chances of the Astro van front/rear bias being the same as your Bronco are slim to none. Buy a proportioning valve and take it out to a parking lot and adjust until you have it set right so front/rear lock up equally.

You may want to pick up a power steering cooler:
PRM-1007 Perma-Cool Compact Fluid Coolers Fluid Cooler

the rest of the parts needed, you should be able to pick up locally.


Putting It Together:

Some of these pictures may be confusing because they are a mix of pre and post Explorer 5.0 install. The basics are the same.

I chose to modify the astroboost bracket to use the existing Bronco master cylinder holes. I had to chop the corner to make room for one of the bolts on the firewall



You will need to open up the hole in the firewall a bit so the nut on the hydroboost bracket fits inside.

You can mount the hydroboost in any orientation. Whatever works. This can get very complicated with EFI because of the upper intake. Having a body lift also changes things. Angle brackets are available that point the hydroboost and master cylinder towards the driver's side to make room for the upper intake.

In my case, when I went EFI, I was strongly opposed to using an angle bracket so I flipped my upper intake and did some customization to the Explorer 5.0 elbow so it would all fit: (just barely)



here is a picture of the final product with my 302 and canned ham pump:


you will need to cut, thread and "splice" your astro/bronco pushrods together:






Use a long coupler, lock nuts, thread lock... Whatever it takes for those 2 pieces to never come apart.

here is looking at the back of the canned ham pump:


and from the bottom of the steering box:


The bracket installed on the firewall. Use the existing MC bolts just drill new holes on the plate. (not the corner cut to clear the screw)


the brake prop valve:




replacing the small rear drum brake reservoir with a large one. This is a great mod if your rear cylinders leak. Just pop the small one off and put the large one on.


hard to see, but you can get an idea of the routing on the Explorer 5.0


power steering cooler:


use a brass Tee for the return lines and put the Tee as close as possible to the reservoir.

here is a routing diagram:


Once you get everything connected, put the front end up on jacks and turn the steering lock to lock while pressing the brakes 700 times. Maybe more

make sure you keep the reservoir full so it doesn't suck more air making things worse.

good info. do they make the lines premaid with the swivel fittings? i hate building those hoses.

mavereq said:

good info. do they make the lines premaid with the swivel fittings? i hate building those hoses.

Click to expand...

a hydraulic shop could probably make them for you but it is super easy with the russel powerflex. Mavereq, If you can build a 4-link you can make hose ends it literally only takes a minute.

i know i can do it; i just hate making hoses. i always end up with wire up under my fingernails. that crap gets old. i know you can buy -6 braided lines premaid. i just wasnt sure if you could get the stuff made for power steering premade the same way.

ok, i'm done whining. i need to get some work done today.

another nice mod is to use a master cylinder reservoir off of the same vintage Chevy S10 Blazer.

The benefit is that both reservoirs are the same larger size but they are made as one unit making them stronger.

The individual units can move around and the nipple breaks off in the the master cylinder itself.

When you use the can ham , did you run 2 return lines to the remote reservoir
and 1 to the can ham ?

there's no remote reservoir with a canned ham Saginaw pump. The pump is the reservoir. Just put short length of hose and a T on the return tube on the pump, then run your steering gear and h-boost returns to both sides of the T.

DanWheeler said:

there's no remote reservoir with a canned ham Saginaw pump. The pump is the reservoir. Just put short length of hose and a T on the return tube on the pump, then run your steering gear and h-boost returns to both sides of the T.

Click to expand...

I'm in the middle of all this right now.. Trying to remember.. Doesn't it matter where the returns go on the Tee? meaning the return from the booster gets the strait shot into the res. and the sector goes to the 90 deg side of the tee? Is this right?

I guess I'm not entirely sure. I never had any problems with mine with the returns pointing straight into each other on the T

i bought one of the filters from bcb. it has two inlets and one outlet and works in place of the t.

bronco-billy-66 said:

I'm in the middle of all this right now.. Trying to remember.. Doesn't it matter where the returns go on the Tee? meaning the return from the booster gets the strait shot into the res. and the sector goes to the 90 deg side of the tee? Is this right?

Click to expand...

It does matter to a certain extent. The straight shot of the Tee is for the steering and the 90 degree part is for the brake return. Less turbulence and bubbles. Ideally you would tap another return line. I used the Tee with no problems so far.

I am working on this now too. I thought the hb return had the straight shot to avoid slow pedal return. The the steering box was on the 90 degree leg. I don't KNOW just what I read and did. My pump is shot so I am not running yet.

While you're scrounging the jy for your hydroboost setup, stroll over to the truck section and pull the reservoir (or the whole pump) off of a hydroboost equipped 1 ton Chevy truck.....paid about $7 for it ;D ----------Hans

Just to muddy the waters a little bit.. I just checked the pressure fitting size on my 4x4x2 box... Its 1/2-20 inverted flare...so I guess some are different.. Check yours before ordering

powerflex hose fitting

Dan,

Saw your post and had some questions concerning the hose fittings. I probably spent 1 hour making each fitting only to have one blow apart (fitting came seperated from hose) as soon as I ran the engine. I was worried this would happen because the only way I could get the small ferrule to fit inside the teflon tubing was to make 4 small cuts at the end of the hose (so the hose would "flower" out). I know this is not in the instructions but it seemed there was no way that ferrule was ever going to fit. DO you have any hints. would warming (not heating) the tubing work?

Mike

mgb0302 said:

Dan,

Saw your post and had some questions concerning the hose fittings. I probably spent 1 hour making each fitting only to have one blow apart (fitting came seperated from hose) as soon as I ran the engine. I was worried this would happen because the only way I could get the small ferrule to fit inside the teflon tubing was to make 4 small cuts at the end of the hose (so the hose would "flower" out). I know this is not in the instructions but it seemed there was no way that ferrule was ever going to fit. DO you have any hints. would warming (not heating) the tubing work?

Mike

Click to expand...

hmm, that doesn't sound right - what fittings and hose did you get? I didn't have to do anything special to make things work. as long as you have the russel powerflex hose and fittings it should all work together with no flaring required.

mgb0302 said:

Dan,

Saw your post and had some questions concerning the hose fittings. I probably spent 1 hour making each fitting only to have one blow apart (fitting came seperated from hose) as soon as I ran the engine. I was worried this would happen because the only way I could get the small ferrule to fit inside the teflon tubing was to make 4 small cuts at the end of the hose (so the hose would "flower" out). I know this is not in the instructions but it seemed there was no way that ferrule was ever going to fit. DO you have any hints. would warming (not heating) the tubing work?

Mike

Click to expand...

The ferrule goes on the outside of the teflon liner and the inside of the braid.It will press between them. I just went through this a month or so ago.

This a great post. I just used it to order what I need for my PS and HB install. Thanks a bunch for posting this info.

Izzy, glad the information helped. I found some of my old notes that may answer the questions you PM'ed me:

Saginaw pump output = M16x1.5 or 3/8ths inverted flare (or proprietary if Ford Explorer pump)
Hydroboost high pressure input (from pump) = M16x1.5
Hydroboost output (to gearbox) M18x1.5
Hydroboost low pressure return (to reservoir) = 3/8ths nipple
4x4x2 steering box input (from hydroboost) = 5/8-18 inverted flare
4x4x2 steering box return (to reservoir) 3/8ths inverted flare

I'm not positive about the gearbox return being 3/8ths but I think so.

which one of these was your input, the driver or passenger side?